Amalgam housing means for a fluorescent lamp

ABSTRACT

The invention relates to fluorescent lamps with an amalgam. The disclosed fluorescent lamp with an amalgam comprises within its internal space means for housing the amalgam thereinside, one end portion of said means being positioned in the hightemperature zone of the lamp, adjacent to the cathode thereof, the opposite end portion of said means being positioned in the low-temperature zone of said lamp, adjacent to the base thereof. Said means can be adapted either for free displacement of the amalgam thereinside, when the lamp is to be mounted into a light fixture, or for retaining said amalgam in a fixed desired position thereinside.

United States ?atent Fedorenko et al.

[451 Aug. 29, 1972 [S4] AMALGAM HOUSING MEANS FOR A FLUORESCENT LAMP 3,160,778 12/1964 Dziergwa et a1. ..313/l09 X Primary Examiner-Roy Lake Assistant Examiner-Palmer C. Demeo AttorneyWaters, Roditi, Schwartz & Nissen 57 ABSTRACT The invention relates to fluorescent lamps with an amalgam.

The disclosed fluorescent lamp with an amalgam comprises within its internal space means for housing the amalgam thereinside, one end portion of said means being positioned in the high-temperature zone'of the lamp, adjacent to the cathode thereof, the opposite end portion of said means being positioned in the lowtemperature zone of said lamp, adjacent to the base thereof.

Said means can be adapted either for free displacement of the amalgam thereinside, when the lamp is to be mounted into a light fixture, or for retaining said amalgam in a fixed desired position thereinside.

3 Claims, 4 Drawing Figures [72] Inventors: Anatoly Stepanovich Fedorenko, ulitsa Svetotekhniki, 19, kv. 53; Jury Alexeevich Mescheryakov, ulitsa A. Nevskogo, 127, kv. 24; Alexandr Alexandrovich Prytkov, ulitsa Svetotekhniki, 57, kv. 43, all of Saransk Massr; Vladimir Vasilievich Tyabirdin, ulitsa Zygina, 42, kv. 45, Poltava, all of U.S.S.R.

[22] Filed: Nov. 17, 1970 [21] Appl. No.: 90,270

[52] US. Cl ..313/109, 313/174 [51] Int. Cl. ..H0lj 61/28 [58] Field of Search ..313/109, 174

[56] References Cited UNITED STATES PATENTS 3,089,972 5/1963 Larson et al. ..313/109 X 2,280,618 4/1942 Besson ..313/174 X P'A'TENTED M1929 1912 SHEEI 2 BF 2 AilllliillIlllllllilillil. A

AMALGAM HOUSING MEANS FOR A FLUORESCENT LAMP The present invention relates to gas discharge light sources, and, more particularly, it relates to fluorescent lamps in which the dependence of the light flux of the lamp on the temperature of the ambient air is controlled by appropriate positioning of the amalgam in the zones of the lamp, having different temperatures during operation of the lamp.

Known in the art are lamps with an amalgam, adapted for operation at relatively high ambient temperatures (in light fixtures of the closed type, in poorly ventilated light fixtures, in premises with heated ambient air, etc.). The amalgam in such lamps is positioned in special housing devices in the relatively cool zones of the lamp (the central portion of the glass envelope, the exhaust tube, and so on). Manufacture of such lamps involves the use of special production and assembling equipment which should provide for cooling the zone, where the amalgam is positioned, in the course of the thermal treatment of the lamp and during vacuumation of the lamp, when the amalgam is positioned in the central portion of the glass envelope; when the amalgam is positioned in the exhaust tube, this equipment should effect positioning of either two or three additional members into the exhaust tube (i.e. of the amalgam and the retaining means preventing accidental displacement of the amalgam in the exhaust tube).

Fluorescent lamps with an amalgam can be also manufactured for operation under the conditions of the normal air temperature, i.e. in light fixtures of the open type. In this case the amalgam is to be positioned in the relatively high-temperature zone of the lamp, for the amalgam to decompose into mercury condensing out in the cooler portions of the lamp and the amalgamated metal. The mercury vapor pressure inside the lamp depends in the last-mentioned case on the temperature in the condensation zone, and such a lamp, like a lamp with pure mercury, has its light flux at its maximum at the normal temperatures of the ambient air.

A disadvantage of the two abovedescribed known structures of fluorescent lamps with an amalgam, adapted for different operating conditions, is the fact that the two types cannot be produced at the same assembling production line, without the necessity of rearranging this line to a considerable extent, when switching from one of the two types to the other one. This, in turn, involves the use of several types of production equipment and accessories, the unwanted waste of time and effort for re-arranging the equipment, and, as a result, is reflected in an increased production cost of the lamps.

It is an object of the present invention to eliminate the above-mentioned disadvantages.

The main object of the present invention is to provide a fluorescent lamp with an amalgam, of which the temperature characteristics of the operation can be varied without the necessity of rearranging the production equipment used for the manufacture of such lamps, this being attained due to the modified construction of the amalgam-housing means of the lamp.

This object is accomplished in a fluorescent lamp with an amalgam, having within the internal space of said lamp means for housing said amalgam, in which lamp, in accordance with the present invention, said means has one end portion thereof positioned in the high-temperature zone of said lsmp, adjacent to the cathode thereof, said means having the opposite end portion thereof positioned in the low-temperature zone of said lamp, adjacent to the base thereof.

It is expedient for said amalgam-housing means to include the exhaust tube of said lamp, having one end portion thereof positioned adjacent to the cathode of the lamp and the other end portion thereof positioned in the base portion of the lamp.

It is also expedient for said exhaust tube of the lamp to include a tubular member having in the opposite end portions thereof substantially spherically expanded portions adapted to retain therein the amalgam of the lamp, when the lamp is mounted in a light fixture for operation in a horizontal position, the respective dimensions of the tubular member and the amalgam being so selected that the amalgam can be freely displaced within said tubular member.

' It is alternatively expedient for said means housing thereinside said amalgam to include a container mounted in the exhaust tube of the lamp and retained at the side thereof, facing the cathode, by a bracket connected to the electrode wire of the lamp.

It is further expedient for said container to include a tubular member having the opposite end portions of the wall thereof bent inwardly, the amalgam being retained in said tubular member by at least one auxilia-. ry tube having a smaller diameter than said tubular member.

A fluorescent lamp with an amalgam, constructed in accordance with the present invention, provides for varying the dependence of the light flux on the ambient temperature without the necessity of rearranging the considerably the production equipment employed for the manufacture of such lamps. The dependence of the light flux of the lamp embodying the present invention, wherein the amalgam-housing means includes a container on the ambient temperature can be varied by merely turning the container through in the longitudinal plane thereof, when the container is introduced into the lamp in the course of the assembling operation; alternatively, this dependence can be varied by varying the lengths of the abovementioned auxiliary tubes retaining the amalgam in a desired position in the container. Moreover, assembling of the container can be performed outside the main assembly line, as a preparatory operation, whereby the productivity of the main assembling equipment can be stepped up. If the amount of the respective types of the lamps with different temperature characteristics, is known beforehand which are to be manufactured, is known beforehand, the manufacturer is able to prepare the corresponding quantities of the respective types of the containers with different positions of the amalgam and then to use these containers without re-arranging the assembling equipment, because the containers for lamps with different temperature characteristics have the same dimensions. This feature is particularly important for the manufacturers of fluorescent lamps having different temperature characteristics of their operation, because the manufacturers can produce a greater amount of such lamps without increasing the amount of the assembling equipment.

The dependence of the light flux on the ambient temperature in lamps constructed in accordance with the present invention, having their amalgam-housing means in the form of the exhaust tube of the lamp, can be selectively varied (i.e. either of the two types of such dependence can be selectively chosen) directly by the user of such a lamp, by displacing the amalgam of the lamp into the corresponding end portion of the exhaust tube. It should be particularly mentioned that when the exhaust tube of the lamp, constructed in accordance with the present invention, is used for housing thereinside the amalgam of the lamp, the lamps can be manufactured for installation either in a light fixture of the closed type, or in a light fixture of the open type without any necessity of rearranging the production and assembling equipment, even as far as the preparatory operations are concerned. It is also worth mentioning here that the structure of a lamp, wherein the exhaust tube is used as the means for housing the amalgam, becomes particularly valuable when the manufacturer has no knowledge of the future operating conditions of the lamps, and it is up to the user to choose the appropriate temperature characteristics of the operation of the lamps he acquires.

Thus, it becomes possible to eliminate the necessity of specifying the precise amount of the lamps of different types, as far as the temperature characteristics of their operation is concerned, when the lamps are ordered at the manufacturers; moreover, the manufacturer does not have to plan separately the amount of the lamps adapted for installation in light fixtures of the closed type and those of the open type.

The herein dislosed structure of a fluorescent lamp with an amalgam, embodying the invention, also provides for improving the hygienic conditions of the work of operators engaged in the production of the lamps, as well as for cutting down considerably the amount of mercury issuing from a lamp when it is broken in operation or during installation.

The present invention will be better understood from the following detailed description of two preferred embodiments of the invention, with reference being had to the accompanying drawings, wherein:

FIG. 1 is an axial sectional schematic view of the end portion of a lamp, constructed in accordance with one embodiment of the present invention, in which the amalgam-housing means is in the form of the exhaust tube of the lamp;

FIG. 2 is an axial sectional schematic view of the end portion of a lamp, constructed in accordance with another embodiment of the present invention, in which the amalgam-housing means is in the form of a separate container;

FIG.3 (a, b, c) shows alternative ways of positioning and retaining the amalgam in the separate container in a lamp, embodying the invention;

FIG. 4 shows in graphical form the relationship between the light flux of a fluorescent lamps with an amalgam, constructed in accordance with the present invention, and the ambient temperature, as relates to different positions of the amalgam in the amalgamhousing means of the lamp.

Referring now in particular to the appended drawings, it can be seen from FIG. 1 that the fluorescent lamp with an amalgam, embodying the invention, comprises a glass envelope 1 coated with a fluorescent layer 2 and a pair of mounts or stems of which one does not include an exhaust tube (this stem is not shown in the appended drawings), and the other stem 3 includes an exhaust tube 4 which also acts as means for housing the amalgam. The two electrode wires 5 of the stem 3 carrying the tungsten cathode 6 coated with an electronemissive layer. The external ends of the electrode wires 5 are soldered to the respective ones of the two current leads or pins 7 of the base 8 of the lamp. The exhaust tube 4 extends beyond the confines of the press 9 of the stem 3 both into the base 8 and into the main space of the herein disclosed lamp, toward the cathode 6. The opposite end portions of the hollow exhaust tube 4 are provided with substantially spherically expanded hollow portions 10, whereas the portion of the exhaust tube 4, which extends through the press 9, has an aperture 1 1 for vacuumization of the lamp. The exhaust tube 4, as it has been already mentioned, houses thereinside the amalgam 12, e.g. in the shape of a ball of which the diameter is somewhat smaller than the internal diameter of the exhaust tube 4 and somewhat greater than the diameter of the aperture 11. Alternatively, the amalgam 12 can be shaped as a cylinder, a cube, etc.

The operation of the herein disclosed fluorescent lamp with the amalgam is, as follows.

When the herein disclosed lamp is mounted for operation in a light fixture of the closed type, i.e. for operation with a comparatively high ambient temperature, the amalgam 12 is displaced into the substantially spherical expanded portion 10 of the exhaust tube 4 in the base portion 8 of the lamp, before the lamp is mounted into the light fixture. For the herein disclosed lamp to operate properly under such conditions, the composition of the amalgam 12 is so selected that the light flux of the lamp should be at its maximum at an elevated temperature of the ambient air, which situation is represented by the curve x in FIG. 4.

On the other hand, when the herein disclosed fluorescent lamp is mounted for operation in a light fixture of the open type, i.e. for operation with the normal ambient temperature, the amalgam 12 is displaced into the spherical expanded portion 10 of the exhaust tube 4, positioned adjacent the cathode 6, before the lamp is mounted into the light fixture. Thus the temperature of the amalgam 12 is high, and the pressure of mercury vapors inside the lamp is defined by the temperature of mercury which has vaporized from the amalgam l2 and condensed out on the cooler portions of the lamp. In the last-described case the light flux of the lamp is at its maximum at the normal temperature of the ambient air, as represented by the curve y in FIG. 4.

For the amalgam 12 to be displaced into the hightemperature zone (i.e. into that one of the expanded portions 10 of the exhaust tube 4, which is adjacent to the cathode 6) the lamp, prior to being mounted into the light fixture, should be positioned for a short period vertically, with that end of the lamp, which bears thereon the appropriate markings, facing upwardly. Then, in case the lamp is to be operated in a horizontal position, it should not be rotated in a vertical plane through an angle in excess of when it is mounted into the light fixture. In other words, in this case the lamp should be introduced into the light fixture from below with the markings-bearing end first. Alternative- 1y, when the amalgam 12 is to be displaced into the lowtemperature zone, i.e. into that expanded portion of the exhaust tube 4, which is positioned in the base portion 8 of the lamp, the lamp, prior to being mounted into the light fixture, should be positioned vertically, with the end thereof bearing the markings facing downwardly. Thereafter, in case the lamp is to be operated in a horizontal position, it should not be rotated in a vertical plane through an angle in excess of 90, when it is mounted into the light fixture, i.e., it is introduced into the light fixture from below with the end bearing no markings first.

According to another embodiment of the present invention, illustrated in FIG. 2, the fluorescent lamp has a glass envelope 1 coatedwith a light producing layer 2, and a pair of mounts, or stems of which one is not provided with an exhaust tube (this stem is not shown), and the other one 13 has an exhaust tube 14 secured in the stem 13 so that it forms an extension of the cylindrical passage 15 made in the press 9 of the stem 13. The stem 13 has a pair of current leads 5 having their respective external end portions connected to the connection pins 7 of the base 8 of the lamp, whereas the respective internal end portions of the leads 5 are connected to the tungsten cathode 6 provided with an electron-emissive coating. One of the current leads 5 has welded thereto a bracket 16 in the fonn of a discshaped petal. The exhaust tube 14 houses therein a container 17 which is illustrated separately in more detail in FIG. 3, a, b, c, this container 17 including a tube 18 in which the amalgam 12 is retained by either a single auxiliary tube 19 or by two such auxiliary tubes. Displacement of the container 17 in the exhaust tube 14 and in the passage 15 is limited, on the one hand, by the bracket 16, and on the other hand by the closed end of the exhaust tube 14. The dependence of the light flux of the lamp illustrated in FIG.2 on the ambient temperature is determined by the position of the amalgam 12 in the container 17. The lamp in which the amalgam 12 is positioned adjacent to the cathode 6 (FIGS. 2 and 3 a), has its maximum light flux at the normal temperature of the ambient air (curve y in FIGA), and thus is adapted for installation in open-type light fixtures. On the other hand, the lamp in which the amalgam 12 IS positioned in the base portion 8 (FIG. 3 c), has the maximum light flux at an elevated temperature of the ambient air (as represented by the curve x in FIGA) and thus is adapted for installation in light fixtures of the closed type.

It is also possible to position and retain the amalgam 12 in the areas of the tube 18 of the container 17, which are at intermediate temperature in operation of the lamp, i.e. at temperatures insufficient for decomposition of the amalgam 12. Such a position of the amalgam 12 is illustrated in FIG.3 b. In this last-mentioned case the dependence of the light flux of the lamp on the ambient temperature is represented by the curve z in FIG.4 i.e. this relationship holds an intermediate position in respect to the dependence represented, respectively, by the curves x and y in the same FIG.4.

What we claim is:

l. A fluorescent lamp with an amalgam, comprising: a glass envelope coated with a fluorescent layer and having an end portion thereof associated with a base of said lamp; a plurality of stems ositioned within said envelope; means for ousing sax amalgam, said means being positioned in one of said plurality of stems; each said stem being associated with at least two electrode wires connected with a cathode; said housing means having one end portion thereof positioned in the hightemperature zone of said lamp adjacent to said respective cathode, said housing means having the opposite end portion thereof positioned in the low-temperature zone of said lamp adjacent to said base thereof, said housing means including an exhaust tube means for said lamp, said exhaust tube means including a tubular member provided with a pair of substantially spherically expanded portions adjacent to the respective op-v posite ends of said tubular member, said expanded portions being adapted to retain said amalgam interiorly thereof when said lamp is installed in a light fixture for operation in -a horizontal position, the respective dimensions of said tubular member and said amalgam being selected so as to permit free displacement of said amalgam within said tubular member.

2. A fluorescent lamp with an amalgam, comprising: a glass envelope coated with a fluorescent layer and having an end portion thereof associated with a base of said lamp; a plurality of stems positioned within said envelope; means for housing said amalgam, said means being positioned in one of said plurality of stems; each said stem being associated with at least two electrode wires connected with a cathode; said housing means having one end portion thereof positioned in the hightemperature zone of said lamp adjacent to said respective cathode, said housing means having the opposite end portion thereof positioned in the low-temperature zone of said lamp adjacent to said base thereof, said housing means including an exhaust tube means for said lamp, said means for housing said amalgam including a container mounted in said exhaust tube means for said lamp, said container being retained at the end thereof, facing said cathode, by a bracket means connected with one of said electrodes of said lamp.

3. A fluorescent lamp, as claimed in claim 2, wherein said container includes a tube having the opposite end portions of the wall thereof bent inwardly, said amalgam being retained in said tube at least from one side by an auxiliary tube having a smaller diameter than said first-mentioned tube. 

1. A fluorescent lamp with an amalgam, comprising: a glass envelope coated with a fluorescent layer and having an end portion thereof associated with a base of said lamp; a plurality of stems positioned within said envelope; means for housing said amalgam, said means being positioned in one of said plurality of stems; each said stem being associated with at least two electrode wires connected with a cathode; said housing means having one end portion thereof positioned in the high-temperature zone of said lamp adjacent to said respective cathode, said housing means having the opposite end portion thereof positioned in the low-temperature zone of said lamp adjacent to said base thereof, said housing means including an exhaust tube means for said lamp, said exhaust tube means including a tubular member provided with a pair of substantially spherically expanded portions adjacent to the respective opposite ends of said tubular member, said expanded portions being adapted to retain said amalgam interiorly thereof when said lamp is installed in a light fixture for operation in a horizontal position, the respective dimensions of said tubular member and said amalgam being selected so as to permit free displacement of said amalgam within said tubular member.
 2. A fluorescent lamp with an amalgam, comprising: a glass envelope coated with a fluorescent layer and having an end portion thereof associated with a base of said lamp; a plurality of stems positioned within said envelope; means for housing said amalgam, said means being positioned in one of said plurality of stems; each said stem being associated with at least two electrode wires connected with a cathode; said housing means having one end portion thereof positioned in the high-temperature zone of said lamp adjacent to said respective cathode, said housing means having the opposite end portion thereof positioned in the low-temperature zone of said lamp adjacent to saiD base thereof, said housing means including an exhaust tube means for said lamp, said means for housing said amalgam including a container mounted in said exhaust tube means for said lamp, said container being retained at the end thereof, facing said cathode, by a bracket means connected with one of said electrodes of said lamp.
 3. A fluorescent lamp, as claimed in claim 2, wherein said container includes a tube having the opposite end portions of the wall thereof bent inwardly, said amalgam being retained in said tube at least from one side by an auxiliary tube having a smaller diameter than said first-mentioned tube. 